People usually don’t believe me when I tell them how quickly we built the first version of Flightcaster, a flight-tracking app I founded in 2009. It was not a trivial piece of technology, and we launched a Web app, an iPhone app, and a Blackberry app simultaneously. And all of this was done in a little over three months, from first line of code to product launch. At the time, it was the most productive any of us had ever been in our lives. It was awesome.

The reason we were able to focus and motivate ourselves was because we were part of the summer 2009 YCombinator batch. One of the great aspects of being in YCombinator is that the date of Demo Day is set for you. Paul Graham doesn’t go around asking each start-up when would be a convenient time for them to be ready. The date is set and every company has to do what it takes to be ready in time.

The Power of DeadlinesThis concept of setting the time limit first and adjusting the scope accordingly is really powerful. And the opposite is just as powerful. I don’t really remember anything concrete being accomplished in the 100 days after Demo Day. And we didn’t really accomplish very much in the 100 days after that either. Without any clear ambitious goals, we simply drifted towards a less productive state. And when our product ran into trouble we were too slow to react.

When we got into Y Combinator for my current company, 42Floors, a search engine for commercial real estate, we had no code written. But we managed to create a complete platform in less than 10 weeks. Once again, we achieved a level of productivity that had seemed impossible at the beginning. But I wanted to see if we could keep the momentum going. After Demo Day, I went and bought a 100-day goal calendar.

Counting Down From 100We’re now on our sixth 100-day countdown book. Across our walls at the 42Floors office, we have the final pages of a handful of 100-day books framed with the accomplishment listed and the signatures of every member of the team. (There’s red tape across the periods when we didn’t meet our goal.) I have enough data to say that this system has worked without burning us out.

If you want to push your company (and yourself) to achieve more ambitious goals, I highly recommend you give this a try. Here are my six tips for creating your own 100-day objectives:

1. Always set the deadline first.This is seriously the most important step. If you think about scope and then try to predict a deadline, you are always going to be in this mindset of time estimation. But when you pick the deadline first, and then try to pick the goal, you begin to see how ambitious you can really get.

2. Tell everyone about the 100-day goal.After we decided that launching in New York was a 100-day goal, we told our investors and partners about the launch date. We didn’t mention that it was part of some 100-day goal program--we just told them with certainty the date of the launch. That act put even more pressure on us to make sure that we hit that deadline. It really helps when everyone believes the deadline will hold--and there's nothing like external pressure to help with that.

3. Make it front and center.Deadlines don’t work unless people can see them. We have a morning ritual of ripping another day off of the countdown booklet. It also serves as a conversation piece for anyone who walks in the office--people want to know what is happening in 27 days, and we tell them. And in doing so, we remind ourselves that we have a goal to accomplish: We need to get to work.

4. Assign individual goals.While the 100-day goal is a shared communal responsibility, it is helpful for each individual to know exactly what they need to contribute.

5. Delay the wouldn’t-it-be-cool-ifs.We are never short on good ideas. But to accomplish a big goal, you need the discipline to stay focused on doing one thing at a time and doing it well. We have a simple way of dealing with those “wouldn’t-it-be-cool-if” conversations: We just push them back to our next 100-day planning session. This raises the bar on what it takes to introduce a change to the middle of the 100 days. It’s not that we won’t deviate from our plan--we deviate from plans all the time--it’s that we will only do so when it is actually really important and not just interesting.

6. Celebrate!The last 20 days of a 100-day segment are really stressful, but there's nothing wrong with working hard. And it's immediately followed by some much-needed rest. When we hit our 100-day mark, it feels awesome. We plan something big to celebrate--we all go out and take stock of the accomplishment. I've been an entrepreneur long enough to know that a good portion of a start-up’s life is spent in the trough of sorrow, so having something to celebrate rocks.

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